Double-sealed, bearingless, reciprocating conveyor with slat-supporting guide trough subdecks

ABSTRACT

A reciprocating slat conveyor includes a plurality of laterally and substantially parallel longitudinal trough-like subdecks and a plurality of longitudinal slats adjacent to and parallel to each other. The slats are in a sliding relationship with a pair of adjacent subdecks and cover the longitudinal space between the pair of adjacent subdecks. The subdecks longitudinally support two adjacent slats at or near a slat longitudinal side edge. The subdecks conduct the movement of the slats, preferably without distinct bearing elements therebetween. Some preferred embodiments include raised double-seal system.

The present application is a continuation-in-part of U.S. Patentapplication Ser. No. 12/332,335 (now U.S. Pat. No. 7,926,646), filedDec. 10, 2008, the disclosure of which is expressly incorporated hereinby reference in its entirety.

BACKGROUND OF INVENTION

This invention relates to reciprocating slat-type conveyors, and moreparticularly to bearingless, reciprocating slat-type conveyors in whichthe longitudinal edges of the slats are supported by guide troughsubdecks.

Reciprocating slat-type conveyors (also referred to as “conveyorsystems,” “live floor conveyors,” “reciprocating slat conveyors,” or“conveyors”) generally include a plurality of elongated slats (alsoreferred to as “conveyor slats,” “floor slats,” or “deck slats”). Theconveyors are generally used in the load-holding compartment of loadtransport vehicles (e.g. a mobile cargo trailer, bed of a truck (truckbed), rear portion of a semi-trailer, or container portion of avan-truck). The slats are arranged side-by-side to form the floor of theload-holding compartment so that they extend longitudinally to theframework of the load-holding compartment. A “load” may be, for example,grain, fertilizer, soil, sand, shredded documents, chipped wood,sawdust, garbage, or any particulate matter.

The slats are generally grouped such that one group of slats (a groupgenerally includes at least three slats although it is to be understoodthat each group may include any desired number in excess of two) movessimultaneously in one direction (the “load-conveying direction”) andthen returns one slat at a time (in the “retraction direction”) to thebeginning position. This operation results in a step-wise advance of theload positioned on the floor followed by a retraction of the slatswithout moving the load.

Early live floor conveyors used essentially flat reciprocating slats,such as those described in U.S. Pat. Nos. 3,534,875 and 4,143,760 (whichare herein incorporated-by-reference in their entirety). These flatslats rested directly on transverse frame beams and guide beams. Thisconfiguration proved problematic because friction between the slats andthe beams resulted in great amounts of power lost to friction and theslats not moving smoothly on the beams. This was particularly true whenthe slats became wet and/or worn.

To alleviate these problems, the industry began using anti-frictionbearings between the slats and the beams. This is shown in the pervasiveuse of bearings in live floor conveyors including, but not limited tothose shown in U.S. Pat. Nos. 4,144,963, 4,184,587, 4,611,708,4,856,645, 5,088,595, 5,165,525, 5,263,573, 5,267,641, 5,301,798,5,325,957, 5,335,778, 5,547,067, 5,560,472, 5,664,663, 5,727,672,6,257,396, 6,513,648, 6,651,806, 6,763,933, and 7,152,729 and in U.S.Publication No. 2008/0277246. These references are hereinincorporated-by-reference in their entirety. Many of the bearings have astructure similar to that shown in U.S. Pat. No. 4,144,963 (which isherein incorporated-by-reference in its entirety) that describes aplurality of anti-friction bearings made of synthetic thermoplasticresin such as Teflon®, Delrin®, polyethylene, etc., or other suitablematerial having a low coefficient of friction. Each bearing issubstantially U-shape in cross-section, having a top wall andlaterally-resilient side walls to overlap the top and sides of a guidebeam. Each of the side walls is provided with a pair of downwardly andinwardly extending legs such that, when in position, the legs arepositioned inwardly under the opposite sides of the guide beam to securethe bearing against vertical and longitudinal displacement. Bearings,however, can be problematic for many reasons including, but not limitedto that they can slip or become worn, they require a large amount oflabor to install, they require relatively close tolerances for fittingbetween the subdeck and slats, they allow road debris such as dust andsalt to become entrapped between the deck and the bearing thusincreasing wear of the slats, they add weight, and they are expensive toreplace.

Live floor conveyors are often used to convey particulate matter.Sometimes it is undesirable to allow the particulate matter to escapethe live floor conveyor. For example, shredded confidential paper cannot be allowed to escape for legal reasons. Other types of loads such asfeeds and fertilizers should not be allowed to filter through theconveyors and onto the ground while the system is in the operating mode.The filtering of chicken feed, for example, to the ground attracts wildbirds which in turn can bring disease to flocks of young chickens andother fowl. U.S. Pat. No. 4,727,978 (which is hereinincorporated-by-reference in its entirety) is a reciprocating conveyorformed of at least one group of slats of inverted U-shape that arespaced apart laterally. The downward side sections of adjacent slats arepositioned within an elongated trough into which the particulate matteris deposited. It should be noted that because the troughs do not supportor guide the slats, additional structures such as tubular supportmembers and bearing members must be used.

U.S. Pat. No. 4,611,708 (which is herein incorporated-by-reference inits entirety) is directed to a system that has floor members (slats)that are supported on guide beams with bearing means between the floormembers and the guide beams. Channels are formed between the guidebeams. Matter such as refrigerated air, small particles of ice, water,and garbage are allowed to enter into the channel space. One problemwith this conveyor is that large particles can collect in the channeland remain in the channel after the load has been unloaded. When theparticles are confidential documents this problem is not tolerable. Whenvarious cargos are being hauled with the same conveyor it is undesirableto mix the cargos. Mixing would occur with this open channel floor.Another problem is that the position of the slat on the guide beam isnot very stable. The wide slat is supported only along the length of itscenter and, therefore, any heavy object sitting offset on the slat cancause the slat to tip on its side and cause uneven wear.

U.S. Pat. No. 5,727,672 (which is herein incorporated-by-reference inits entirety) is directed to a system that uses four primary components:pultruded conveyor slats, bearings, guide members, and support members.The slats have downwardly directed lower sections that grip the guidemembers. The slats also have wing portions that are supported by thebearings that are, in turn, supported by the support members. Thebearings also act as a seal to prevent particulate matter from escaping.If, however, particulate matter gets past the bearing seal, it willescape the conveyor system. Since the pathway for material to escape hasa horizontal portion and a downward portion it is natural for materialto leak. In other words, there is little resistance to leakage exceptfor the weight of the load on the slat on the seal. Also, there islittle to prevent material from entering the sliding contact areabetween the bearing and the slat. When particles enter this joint theyreduce the effectiveness of the bearing and cause premature wear.

U.S. Pat. No. 6,257,396 (which is herein incorporated-by-reference inits entirety) is directed to a system that uses three primarycomponents: slats, bearing strips (having a longitudinal groove on thetop surface thereof), and longitudinal beams. The longitudinal beams areshaped like channels. The bearing strips are supported on thelongitudinal beams, but completely enclose the interior of the channels.The slats are longitudinally supported on two adjacent bearing stripsand longitudinal beams. This reference states that particulate matterthat filters between the edges of the adjoining slats falls into thegrooves in the bearing strips and is cleared away during the conveyingprocess and/or routine maintenance. If, however, particulate matter getspast the bearing strip, it will escape the conveyor system. In addition,the pathway for material to escape the cargo area and enter the contactarea between the slat and the bearing is down and horizontal. There islittle resistance to prevent material from entering the sliding contactarea and thereby cause greater resistance to the sliding motion.Finally, the slat must have a stiff cross-section to resist bucklingsince the joint between the subdeck and the deck is very loose.

U.S. Pat. No. 6,513,648 (which is herein incorporated-by-reference inits entirety) is directed to a system that uses three primarycomponents: elongated subdeck sections (which are joined together byliquid-tight seals) with upwardly projecting bearing supports, elongatedbearings that wrap around the upwardly projecting bearing supports, anddeck slats. If this system is functioning properly, it can be extremelyeffective and even liquid tight. However, if the seals fail or are notinstalled properly, there may be at least some places where particulatematter can escape from the conveyor system. In addition, the pathway formaterial to escape the cargo area and enter the contact area between theslat and the bearing is down and horizontal. There is little resistanceto prevent material from entering the sliding contact area and therebycause greater resistance to the sliding motion. The increased frictionalso occasionally causes the bearing to slide off the bearing posts.

There are many trailers produced whose sole function is to be loadedthrough the open ceiling of the trailer with municipal waste, driven toa landfill, and loaded onto a tipping platform and tipped to greatheights to dump the load of waste out the rear door (gate). Thesetrailers are most often called “tipper trailers.” Exemplary tippertrailers are shown and discussed in U.S. Pat. No. 6,019,568 to Bratlie,U.S. Pat. No. 6,860,695 to Chapman et al., and U.S. Pat. No. 7,100,972to Booher. These references are herein expressly incorporated byreference in their entirety.

BRIEF SUMMARY OF THE INVENTION

Described herein are reciprocating slat-type conveyors, and moreparticularly bearingless, reciprocating slat-type conveyors in which thelongitudinal edges of the slats are supported by guide trough subdecks.

One preferred embodiment reciprocating slat conveyor includes aplurality of laterally and substantially parallel longitudinaltrough-like subdecks and a plurality of longitudinal slats adjacent toand parallel to each other. Each slat has a slat top surface, a slatbottom surface, a slat first longitudinal side edge, and a slat secondlongitudinal side edge. Each slat centrally located within theload-holding compartment is in a sliding relationship with a pair ofadjacent subdecks and covers the longitudinal space between the pair ofadjacent subdecks, the pair of adjacent subdecks conducting the movementof the slat. Each subdeck centrally located within the load-holdingcompartment longitudinally supports two adjacent slats at or near a slatlongitudinal side edge.

The subdecks are preferably in a spaced relationship so as to form alongitudinal space between adjacent subdecks. In some preferreddouble-sealed, bearingless, reciprocating slat-type conveyors, drivemechanisms are positioned in the longitudinal spaces between adjacentsubdecks.

In some preferred double-sealed, bearingless, reciprocating slat-typeconveyors, the subdecks are made of a first material and the slats aremade of a second material dissimilar to the first material. In somepreferred double-sealed, bearingless, reciprocating slat-type conveyors,the first material is stiffer than the second material.

In some preferred double-sealed, bearingless, reciprocating slat-typeconveyors, the reciprocating slat conveyor is free from distinct bearingelements between the subdecks and the slats.

In some preferred double-sealed, bearingless, reciprocating slat-typeconveyors, first seals are formed when the slat first longitudinal sideedge of one slat is in sliding relationship with the slat secondlongitudinal side edge of an adjacent slat. In some preferreddouble-sealed, bearingless, reciprocating slat-type conveyors, the slatfirst longitudinal side edge of one slat overlaps with the slat secondlongitudinal side edge of an adjacent slat.

In some preferred double-sealed, bearingless, reciprocating slat-typeconveyors, second seals are formed when upward side projections and/orslat engagers of the subdeck are substantially coextensive and insliding relationship with the slat surfaces (e.g. the slat bottomsurface or legs extending downwardly from the slat).

Also disclosed herein is a reciprocating slat conveyor for use in aload-holding compartment. The reciprocating conveyor includes aplurality of subdecks and a plurality of slats. The plurality ofsubdecks is laterally and substantially parallel to longitudinalsubdecks made of a first material. The plurality of slats islongitudinal slats adjacent to and parallel to each other. The slats aremade of a second material dissimilar to the first material. The conveyoris free from distinct bearing elements between the subdecks and theslats. The first material may be stiffer than the second material. Thesecond material may be stiffer than the first material.

The foregoing and other objectives, features, and advantages of theinvention will be more readily understood upon consideration of thefollowing detailed description of the invention, taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate various exemplary embodiments.

FIG. 1 is a perspective view of a plurality of deck slats movingsimultaneously in a “load-conveying direction.”

FIG. 2 is a perspective view of a plurality of deck slats, one slat fromeach group moving in a “retraction direction” opposite the“load-conveying direction.”

FIG. 3 is a perspective top view of a load-holding compartment of a loadtransport vehicle with a plurality of deck slats removed to showexemplary systems and structures of a hydraulically-powered conveyorsystem.

FIG. 4 is a perspective top view of a load-holding compartment of a loadtransport vehicle with a plurality of deck slats removed to showexemplary substructures of a reciprocating slat-type conveyor such ascross-drives and cross-drive shoes.

FIG. 5 is a perspective view of a section of the deck slats, subdecks,and exemplary substructure of a reciprocating slat-type conveyor of thepresent invention.

FIG. 6 is a longitudinal side cross-sectional view of a load-holdingcompartment of a load transport vehicle showing a deck slat, subdeck,and exemplary substructure of a reciprocating slat-type conveyor of thepresent invention.

FIG. 7 is a cross-sectional view of a section of the floor includingdeck slats, subdecks, and cross-drive shoes of a reciprocating slat-typeconveyor of the present invention taken along a section of the floorwith cross-drive shoes.

FIG. 8 is a cross-sectional view of a section of the floor includingdeck slats and subdecks of a reciprocating slat-type conveyor of thepresent invention taken along a section of the floor without cross-driveshoes.

FIG. 9 is a cross-sectional view of a section of an alternativepreferred embodiment of a floor including first alternative deck slatsand subdecks of a reciprocating slat-type conveyor of the presentinvention taken along a section of the floor without cross-drive shoes.

FIG. 10 is a cross-sectional view of a section of an alternativepreferred embodiment of a floor including second alternative deck slatsand alternative subdecks of a reciprocating slat-type conveyor of thepresent invention taken along a section of the floor without cross-driveshoes.

FIG. 11 is a cross-sectional view of a section of an alternativepreferred embodiment of a floor including third alternative deck slatsand alternative subdecks of a reciprocating slat-type conveyor of thepresent invention taken along a section of the floor without cross-driveshoes.

FIG. 12 is a cross-sectional view of a section of an alternativepreferred embodiment of a floor including fourth alternative deck slatsand alternative subdecks of a reciprocating slat-type conveyor of thepresent invention taken along a section of the floor without cross-driveshoes.

FIG. 13 is a cross-sectional view of a section of an alternativepreferred embodiment of a floor including fifth alternative deck slatsand alternative subdecks of a reciprocating slat-type conveyor of thepresent invention taken along a section of the floor without cross-driveshoes.

FIG. 14 is a cross-sectional view of a section of a tipper retrofitreciprocating slat-type conveyor assembly that may be used forconverting a tipper trailer.

FIG. 15 is a cross-sectional view of a section of a hold down strip ofthe tipper retrofit reciprocating slat-type conveyor of FIG. 14.

FIG. 16 is a cross-sectional view of a section of a subdeck of thetipper retrofit reciprocating slat-type conveyor of FIG. 14.

FIG. 17 is a perspective view of a load-holding compartment having asnap together reciprocating slat-type conveyor assembly, the assemblyhaving some of the slats removed to show the cross-members.

FIG. 18 is an exploded perspective view of anchors and a subdeck of anexemplary snap together reciprocating slat-type conveyor assembly.

FIG. 19 is a cross-sectional view of anchors, subdecks, and slats of anexemplary snap together reciprocating slat-type conveyor assembly.

FIG. 20 is a cross-sectional view of anchors, subdecks, and slats of anexemplary snap together reciprocating slat-type conveyor assembly.

FIG. 21 is a cross-sectional view of anchors, subdecks, and slats of anexemplary snap together reciprocating slat-type conveyor assembly.

FIG. 22 is a cross-sectional view of anchors and a subdeck of anexemplary snap together reciprocating slat-type conveyor assembly.

FIG. 23 is a bottom view of anchors and a subdeck of an exemplary snaptogether reciprocating slat-type conveyor assembly.

FIG. 24 is a side view of anchors and a subdeck of an exemplary snaptogether reciprocating slat-type conveyor assembly.

FIG. 25 is a cross-sectional view of anchors and a subdeck of anexemplary snap together reciprocating slat-type conveyor assembly takenalong line A-A of FIG. 24.

FIG. 26 is a side view of anchors and a subdeck being installed.

FIG. 27 is a perspective expanded view of anchors, subdecks, and a slatof an exemplary snap together reciprocating slat-type conveyor assembly.

DETAILED DESCRIPTION OF THE INVENTION

Before describing the double-sealed, bearingless, reciprocating conveyorwith slat-supporting guide trough subdecks of the present invention,some of the basic concepts of a reciprocating conveyor are discussed.Please note that the terms and phrases may have additional definitionsand/or examples throughout the specification. Where otherwise notspecifically defined, words and phrases are given their ordinary meaningin the art. Exemplary embodiments may be better understood withreference to the drawings, but these embodiments are not intended to beof a limiting nature. The same reference numbers will be used throughoutthe drawings and description in this document to refer to the same orlike parts.

As shown in FIGS. 1-3, reciprocating slat-type conveyors 10 (alsoreferred to as “conveyor systems,” “live floor conveyors,”“reciprocating slat conveyors,” or “conveyors”) generally include aplurality of elongated slats 20 a, 20 b, 20 c (also referred to as“conveyor slats,” “floor slats,” or “deck slats” and referencedgenerally by reference number 20 in FIGS. 5-8). Conveyor systems 10 aregenerally used in the load-holding compartment 12 of load transportvehicles. Exemplary load-holding compartments 12 include a mobile cargotrailer, a bed of a truck (truck bed), a rear portion of a semi-trailer,a cargo container, a container portion of a van-truck, stationary bins,or any mobile or stationary load holder. The load-holding compartments12 have a framework that has a longitudinal direction and a transversedirection perpendicular to the longitudinal direction. Although thelongitudinal direction is generally longer than the transversedirection, these terms are not meant to be so limited. In FIGS. 3 and 4,the longitudinal direction is shown as extending from the front 14 (withthe bulkhead 14 a, the slope sheet 14 b, and the slope sheet wiper 14 c)to the rear 16. The slats 20 (also referred to as 20 a, 20 b, 20 c) arearranged side-by-side to form the floor of the load-holding compartment12 so that they extend parallel to the longitudinal direction of theframework of the load-holding compartment 12. The design of the slats20, including length, width, and thickness, depends upon factorsincluding the dimensions of the floor, the construction material, andthe application(s) for which the conveyor is to be used.

In one preferred double-sealed, bearingless, reciprocating slat-typeconveyor, the slats 20 are arranged in groups of slats (a groupgenerally includes at least three slats 20 a, 20 b, 20 c, although it isto be understood that each group may include any desired number inexcess of two). As shown in FIG. 1, the slats 20 a, 20 b, 20 c movesimultaneously in one direction (the “load-conveying direction”). Then,as shown in FIG. 2, one slat 20 a of each group moves in the oppositedirection (the “retraction direction”), followed by another slat 20 b ofeach group, and so on until all the slats of the groups are retracted.In this double-sealed, bearingless, reciprocating slat-type conveyor,the slats 20 move together taking the load with them, and then the slats20 return to their starting position, with every third slat 20 a, 20 b,20 c moving in unison. The stationary slats (those not currentlyreturning) hold the load at least partially in place until the nextcycle begins. This operation results in a step-wise advance (in theload-conveying direction) of particulate matter positioned on the floorthat may be followed by partial retraction of the particulate matter onthe floor. It should be noted that alternative double-sealed,bearingless, reciprocating slat-type conveyors may use alternative slatsequences shown and described in any of the references that areincorporated-by-reference herein. (For example, some of the referencesdescribe sequences in which a majority of the slats may be movedsimultaneously in the load-conveying direction while the remaining slatsare moved in the opposite, retraction direction.) It should be notedthat the present invention is not to be limited to double-sealed,bearingless, reciprocating slat-type conveyors using these specific slatsequences.

Exemplary double-sealed, bearingless, reciprocating slat-type conveyorsinclude hydraulically-powered conveyor systems such as that shown inFIG. 3. In this shown double-sealed, bearingless, reciprocatingslat-type conveyor, a two-way, variable-speed, hydraulic power unit 40moves the floor and allows for controlled loading, unloading, andprecision metering. The size and location of the power unit 40 dependsupon the application(s) of the conveyor system. Alternativedouble-sealed, bearingless, reciprocating slat-type conveyors may bepowered using power units and structures shown and described in any ofthe references that are incorporated-by-reference herein. It should benoted that the present invention is not to be limited to double-sealed,bearingless, reciprocating slat-type conveyors powered using these powerunits 40 and structures.

FIG. 4 is a perspective top view of a section of subdecks 30 and otherexemplary substructures 42, 44, 46 used to support the slats orphysically connect the power system (including the power unit 40) to theslats 20. The subdecks 30 will be discussed in detail herein. Otherexemplary substructures shown in this figure includes cross-members 42,cross-drives 44, and cross-drive shoes 46. The cross-drive shoes 46 canalso be considered to be part of the drive mechanism along with thepower unit 40 and any structure (e.g. the cross-drives 44) connectingthe cross-drive shoes 46 to the power unit 40. Alternativedouble-sealed, bearingless, reciprocating slat-type conveyors may usealternative substructure and drive mechanisms such as that shown anddescribed in any of the references that are incorporated-by-referenceherein. It should be noted that the present invention is not to belimited to these embodiments of the substructure and drive mechanisms.

Deck Slats and Subdecks

As will be discussed in more detail, the present invention includes aplurality of laterally and substantially parallel longitudinaltrough-like subdecks 30 that are in a spaced relation so as to define alongitudinal opening or space 31 between adjacent subdecks 30. Aplurality of longitudinal slats 20 are adjacent to and parallel to eachother and, in preferred embodiments, are overlapping. Each slat 20centrally located within the load-holding compartment 12 (as opposed tothose slats on the longitudinal edges of the load-holding compartment12—e.g. in some embodiments there is one on the right edge and one onthe left edge) are in a sliding relationship with two adjacent subdecks30. The slats 20 substantially cover the longitudinal space 31 betweenthe two adjacent subdecks 30. Each subdeck 30 centrally located withinthe load-holding compartment 12 (as opposed to those subdecks on thelongitudinal edges of the load-holding compartment 12—e.g. in someembodiments there is one on the right edge and one on the left edge)longitudinally supports two adjacent slats 20. In preferred embodiments,there is a raised double-seal system protecting the channel formed bythe trough-like subdecks 30. The first seal 48 a is formed when the slatfirst longitudinal side edge of one slat is substantially coextensiveand in sliding relationship with the slat second longitudinal side edgeof an adjacent slat (e.g. by overlapping the slats 20). The second seal48 b is formed when upward side projections of the subdeck aresubstantially coextensive and in sliding relationship with the bottomsurface of the slats supported by the upward side projections (e.g.between the slats 20 and the subdecks 30 such that the seal 48 b israised to be near the bottom surface of the slats 20).

FIGS. 5-8 show the deck slats 20, slat-supporting guide trough subdecks30, and exemplary substructure (e.g. the cross-drive shoes 46) of adouble-sealed, bearingless, reciprocating conveyor system 10 of thepresent invention. In preferred embodiments of the present invention,the deck slats 20 and subdecks 30 are made from dissimilar materials.This is one of the means by which the present invention is able tofunction without bearings between the deck slats 20 and subdecks 30.Either the slats 20 or the subdecks 30 may be constructed of alight-weight material that is not stiff enough to prevent buckling dueto longitudinal forces and/or other forces. The other component isconstructed from an adequately stiff material that is capable ofpreventing this buckling. In the preferred embodiments, the deck slats20 are constructed of an anti-friction material such as Extruded HighDensity Polyethelene (EHDP), High-Density Polyethylene (HDPE),Polyethylene High-Density (PEND), synthetic thermoplastic resin (e.g.Teflon®, Delrin®, polyethylene), UHMW plastic (high molecular weightresinous material), or other suitable material having a low coefficientof friction that is known or yet to be developed. The slats 20 may bemade using processes such as continuous or discontinuous extrusion,pultrusion, molding, and other processes known or yet to be developed.It should be noted that, in preferred embodiments, each slat 20 is anintegrally formed single piece (e.g. the legs are integral with the restof the slat). Hallco Industries, Inc. of Tillamook, Oreg. manufacturesslats (Part No. 39-5023) that may be purchased individually or as a set.In the shown embodiments, the subdecks 30 are constructed of a strong,stiff material such as steel, aluminum, or other suitable material thatis stiffer than the slat material and that creates a low friction jointwith the slat, the material being known or yet to be developed. Thesubdecks 30 may be made using processes such as hot or cold rollforming, extrusion, or cold drawing, and other processes known or yet tobe developed. It should be noted that, in preferred embodiments, eachsubdeck 30 is an integrally formed single piece (e.g. the upwardprojections and slat engagers are integral with the rest of thesubdeck). The dimensions shown in the figures and described herein aremeant to be exemplary and are not meant to limit the scope of theinvention. Depending on the material used, the dimensions, and otherrelevant factors, a conveyor system 10 of the present invention may holda maximum load of 15,000 pounds (6,810 kilograms) to 20,000 pounds(9,080 kilograms) and may have a maximum longitudinal length of 20 feet(6 meters) to 25 feet (7.6 meters).

FIGS. 7 and 8 show a preferred exemplary embodiment of the deck slats20. The slats have a front end (positioned substantially near the front14 of the load handling compartment 12, less a clearance), a rear end(positioned substantially near the rear 16 of the load handlingcompartment 12, less a clearance), a top surface 22 a (also referred toas the upper load-bearing surface 22 a), a bottom surface 22 b (alsoreferred to as the lower surface 22 b), a first longitudinal side edge24 a, and a second longitudinal side edge 24 b. Extending downward fromthe slat bottom surface 22 b are a pair of legs 26 a, 26 b, one leg 26a, 26 b at or near each side edge 24 a, 24 b. In the shown embodiment,the slat legs 26 a, 26 b, are inwardly directed L-shaped legs that willengage the subdeck 30. The slat side edges 24 a, 24 b are designed to besubstantially coextensive and in sliding relationship with adjacent slatside edges 24 a, 24 b such as by overlapping or using a shiplap-typeconfiguration. In the shown embodiment of FIGS. 1-8, there is a raisedsealing longitudinal projection 28 extending along, but slightly above,the first longitudinal side edge 24 a of each slat 20. The raisedsealing longitudinal projection 28 has a bottom surface that engages(mates with and provides a substantial seal thereto) the slat topsurface 22 a of the adjacent slat second longitudinal side edge 24 b toform the seal 48 a. If, as shown, the legs 26 a, 26 b are slightlyinward from their respective side edges 24 a, 24 b, the slat 20 hasoutwardly extending protrusions beyond the legs 26 a, 26 b. In the shownembodiment, the raised sealing longitudinal projection 28 is mounted onor integral with the outwardly extending protrusion on the firstlongitudinal side edge 24 a of each slat and the bottom surface of thelongitudinal projection 28 engages the slat top surface 22 a of theoutwardly extending protrusion on the adjacent slat second longitudinalside edge 24 b. The seal 48 a formed by the overlapping slats 20prevents debris and particulate matter from escaping the conveyor system10 by providing floor-length protection. Because these slat surfaceshave a low friction coefficient, the slats 20 are able to move relativeto each other.

FIGS. 7 and 8 show a preferred exemplary embodiment of theslat-supporting guide trough subdecks 30. This adjective-laden term ismeant to highlight several features of the subdecks 30. First, thesubdecks 30 support the slats 20 longitudinally along their longitudinaledges 24 a, 24 b. Second, the subdecks 30 act as a guide or guide beamthat conducts the movement of the slats 20. Third, the subdecks 30 areshaped at least partially like a longitudinal trough or channel(substantially U-shaped with a base and two upwardly extendingprojections) that is able to catch and contain any debris andparticulate matter that passes through the overlapping slats 20 fromescaping the conveyor system 10. The subdecks have a front end(positioned substantially near the front 14 of the load handlingcompartment 12, less a clearance), a rear end (positioned substantiallynear the rear 16 of the load handling compartment 12, less a clearance),an interior surface 32 a, an exterior surface 32 b, a first longitudinalside edge 34 a (also referred to as the first upward side projection 34a), and a second longitudinal side edge 34 b (also referred to as thesecond upward side projection 34 b). In the preferred embodiment, thetop of the upward side projections 34 a, 34 b are slat engagers 36 a, 36b. In the shown embodiment, the slat engagers 36 a, 36 b and the upwardside projections 34 a, 34 b together form a substantially T-shape upwardprojection from the base. It should be noted that the slat engagers 36a, 36 b may have an alternative shape and they may be part of and/orintegral with the upward side projections 34 a, 34 b. The top surfacesof the slat engagers 36 a, 36 b engage the bottom surface 22 b of theslats 20. The inwardly projecting portions (the part towards theinterior of the subdeck) of the slat engagers 36 a, 36 b engage the slatlegs 26 a, 26 b. As shown, this configuration would substantiallyprevent vertical (up-down) movement between the slats 20 and theirsupporting subdecks 30, but would allow substantially free longitudinalmovement (sliding contact) between the slats 20 and their supportingsubdecks 30. The shapes of these features also help to keep loadparticulate matter from getting into the sliding joints between theslats 20 and the subdecks 30. If there is enough load contained in thechannel to lift the slats enough to allow particulate matter into thesliding joint, the slat legs 26 a, 26 b (the “L-shaped portion”) makescontact with the lower surface of the subdeck slat engagers 36 a, 36 band thus creates a stronger seal 48 b to prevent the passage of the loadmatter. Because the surfaces of the slats 20 have a low frictioncoefficient and because the materials from which the slats 20 and thesubdecks 30 are constructed are dissimilar, there is no need for abearing therebetween.

In preferred embodiments, as shown in FIGS. 1 and 6, end caps 50 may bepositioned and secured at the ends of the subdecks 30 near the rear 16of the load handling compartment 12. The end caps 50 plug the holebetween the subdeck and the rear sill of the container (FIG. 4) toprevent load from escaping. A similar arrangement could be placed at thefront end 14 for a really secure container although the wiper 14 c andslope sheet 14 b are designed to prevent load from entering the frontportion of the deck.

FIGS. 9-13 show alternative preferred embodiments of the slats andsubdecks. These embodiments share many of the characteristics of thepreferred embodiment shown in FIGS. 1-8. Another alternative preferredembodiment would contain slats that have longitudinal edges with a trueshiplap design. It should be noted that these alternative preferredembodiments may include additional patentable features.

FIG. 9 shows an alternative slat 70 embodiment with a sealinglongitudinal projection 72 at or near the slat first longitudinal sideedge and with a longitudinal notch 74 near the slat second longitudinalside edge. The sealing longitudinal projection 72 is substantially levelwith the top surface of the slat 70. Sealing longitudinal projections 72mate with respective longitudinal notches 74 of adjacent slats 70 toform a substantial seal therewith. The resulting connection between thesealing longitudinal projections 72 and adjacent longitudinal notches 74has no surfaces higher than the top surface of the slat 70.

FIG. 10 shows an alternative slat 80 embodiment with inwardly directedlongitudinal L-shaped legs 82 a, 82 b at the slat longitudinal sideedges of the slat 80. The first L-shaped leg 82 a has a sealinglongitudinal projection 84 extending substantially perpendicularthereto. The second L-shaped leg 82 b has a notch 86 defined thereindesigned to mate with the sealing longitudinal projection 84. Sealinglongitudinal projections 84 mate with respective longitudinal notches 86of adjacent slats 80 to form a substantial seal therewith. The resultingconnection between the sealing longitudinal projections 84 and adjacentlongitudinal notches 86 makes the floor formed from the top surfaces ofthe slats 80 substantially flat.

FIG. 11 shows an alternative slat 88 embodiment in which the slatlongitudinal side edges 89 a, 89 b are angled or otherwise formed to bein mating relationship. The resulting connection between thelongitudinal side edges 89 a, 89 b makes the floor formed from the topsurfaces of the slats 88 substantially flat.

FIG. 12 shows an alternative slat 90 embodiment with inwardly directedlongitudinal L-shaped legs 92 a, 92 b near the slat longitudinal sideedges of the slat 90. The first L-shaped leg 92 a has an upwardly-angledsealing longitudinal projection 94 therefrom. In this shown embodiment,the upwardly-angled sealing longitudinal projection 94 mates with theintersection of the top of the slat 90 and the second L-shaped leg 92 b.Sealing longitudinal projections 94 mate with respective longitudinalnotches 96 of adjacent slats 90 to form a substantial seal therewith.The resulting connection between the sealing longitudinal projections 94and adjacent longitudinal notches 96 makes the floor formed from the topsurfaces of the slats 90 substantially flat.

FIG. 13 shows an alternative slat 96 embodiment with inwardly directedlongitudinal upside-down T-shaped legs 98 a, 98 b near the slatlongitudinal side edges of the slat 96. In this embodiment, rather thanusing an integral longitudinal projection, a distinct longitudinalsealing member 99 (shown as a solid bar) is used. In this shownembodiment, the longitudinal sealing member 99 mates with the outwardlydirected portions of the T-shaped legs 98 a, 98 b to form a substantialseal therewith. The resulting connection between the longitudinalsealing member 99 and the outwardly directed portions of the T-shapedlegs 98 a, 98 b makes the floor formed from the top surfaces of theslats 96 substantially flat.

FIGS. 10-13 also show an alternative preferred embodiment of the subdeck100. Like the subdecks 30, alternative subdecks 100 have a front end(positioned substantially near the front 14 of the load handlingcompartment 12, less a clearance), a rear end (positioned substantiallynear the rear 16 of the load handling compartment 12, less a clearance),an interior surface, and an exterior surface. The first longitudinalside edge 104 a (also referred to as the first upward side projection104 a) and the second longitudinal side edge 104 b (also referred to asthe second upward side projection 104 b) are preferably upside-down,inwardly-directed L-shaped members. As shown, the “L” of the sideprojections 104 a, 104 b engages the bottom surface of the slats.

Advantages and Features of the Double-Sealed, Bearingless, ReciprocatingSlat-Type Conveyor Described Herein

The simple and elegant use of materials and design in the presentinvention belies the revolutionary nature of the present invention.Although reciprocating conveyors have been produced since at least 1970,they continue to have problems such as those described in the Backgroundof this specification. Although various known reciprocating conveyorssolve some of the problems, most continue to have at least some of theproblems. Also, sometimes the solutions result in additional complexity,expense, weight, installation time, and/or other undesired consequences.The present invention is a complete redesign of conveyor systems(particularly the slats and subdecks) that solves many of the problemsof known reciprocating conveyors and, additionally, reduces complexity,expense, weight, and installation time. This section addresses some ofthe advantages and features of preferred embodiments of the presentinvention.

Preferred embodiments of the conveyor system 10 substantially reduce thecomplexity as compared to prior art conveyor systems. Prior art conveyorsystems have at least three (and usually more) primary components ascompared to the present invention that includes just two primarycomponents—deck slats 20 and subdecks 30. One reason this is possible isbecause the deck slats 20 and subdecks 30 are made from dissimilarmaterials which eliminates the need for distinct bearing componentsbetween the subdecks 30 and the moving deck slats 20. Another reasonthat this is possible is because in the preferred embodiments the slats20 are formed of a material that is inherently friction reducing. Thedesign of the deck slats 20 and subdecks 30 such that sealing mechanismsare integral therewith also reduces the complexity of the system,production costs, weight, and installation time because less componentsare needed. For example, in most of the preferred embodiments (exceptfor the embodiment shown in FIG. 13), the sealing projections areintegral with the slats. Another example is that a seal is formedbetween the slats 20 and subdecks 30. Finally, the multiple-functiondesign and arrangement of the subdecks 30 and slats 20 eliminates theneed for additional components. Separate central support components arenot needed because the subdecks 30 support the slats 20 longitudinallyalong their longitudinal edges 24 a, 24 b. Separate guide components arenot needed because the subdecks 30 act as a guide or guide beam thatconducts the movement of the slats 20. Separate containment troughs arenot needed because the subdecks 30 function as a longitudinal trough orchannel. Elimination of separate components reduces the complexity ofthe system, production costs, weight, and/or installation time.

Preferred embodiments of the present invention reduce or eliminateleakage between the slats 20 and the subdecks 30 for security andcleanliness. Leakage out of the conveyor system 10 is extremelyundesirable for shredded confidential documents as well as other loads.Leakage into the conveyor system (e.g. road contaminants) is alsoextremely undesirable for certain types of loads (e.g. grains and otherfoodstuff). One way that this is accomplished is the use of thelongitudinal trough-like containment subdecks 30 positioned betweenlongitudinal side edges 24 a, 24 b of adjacent slats 20 so as to catchthe fine particulate matter that sifts between the moving slats 20 andprevent it from escaping the conveyor 10. Another way that this isaccomplished is the use of a double-seal system 48 a, 48 b. The firstseal 48a is the overlapping of adjacent slat side edges 24 a, 24 b(accomplished in some preferred embodiments using, for example, theraised sealing longitudinal projection 28). This first seal 48 asubstantially prevents communication of fine particulate matter or othercontaminates between the load-holding compartment and the trough-likecontainment subdecks 30. The second seal 48 b is the seal formed betweenthe longitudinal edges of the slats and the longitudinal edges of thesubdecks. Significantly, this second seal 48 b is not at the bottom ofthe trough-like containment subdecks 30, but is raised to make it moredifficult to breach. This second seal can be a “maze” through which itwould be difficult for matter travel. In the shown exemplary preferredembodiments, at least part of this second seal 48 b is formed when thetop surfaces of the slat engagers 36 a, 36 b are in substantiallycoextensive and sliding relationship with the bottom surface 22 b of theslats 20. In the shown exemplary preferred embodiments, at least part ofthis second seal 48 b is formed when the slat engagers 36 a, 36 b are insubstantially coextensive and sliding relationship with the slat legs 26a, 26 b. As mentioned above, the strength of this second seal isenhanced if the channel fills because the load particulate matter liftsthe slats so that the slat legs 26 a, 26 b (the “L-shaped portion”)makes a stronger contact with the lower surface of the subdeck slatengagers 36 a, 36 b. Both the first and second seals are accomplishedwithout adding components or otherwise compromising the simplicity ofthe present invention.

Preferred embodiments of the conveyor system 10 also have a reducedinstalled weight because the floor can be constructed of light-weightmaterials. The deck weight reduction may be as significant as half theweight of comparable decks formed from aluminum slats. Normally,light-weight material would buckle due to longitudinal forces and/orother forces so using light-weight material is not a simplesubstitution, but required a complete redesign. In preferred embodimentsthe subdecks 30 and the deck slats 20 have been redesigned so thatlight-weight material is closely engaged and longitudinallyside-supported by adequately stiff material to prevent buckling. In theshown embodiments, the slat 20 and subdeck 30 design provides the weakslats 20 with improved support against buckling.

Still another example is that in preferred embodiments the slats 20 andsubdecks 30 are designed so that the slats 20 are supported near theirlongitudinal edges by the parallel spaced subdecks 30 such that thecenter of each slat 20 has a longitudinal opening 31 (the span betweenthe subdecks 30) into which the drive mechanism (e.g. the cross-driveshoe 46) can be placed. This enables both the subdecks 30 and the slats20 to be continuous from the front of the load-holding compartment tothe back of the load-holding compartment. This has the effect ofincreasing strength and decreasing installation time.

Preferred embodiments of the conveyor system 10 also increase thevertical and lateral strength of the floor as compared to prior artconveyor systems. Preferred embodiments of the conveyor system 10 of thepresent invention include the feature of lower operation pressures(because there is less friction when cycling). Preferred embodiments ofthe conveyor system 10 of the present invention include the feature oftighter end seals (as compared to the end seals of aluminum slats). Theends of the slats and subdecks shown in known references are difficultto seal because the open gap is also the joint between two adjacentslats. The present invention allows this difficult area to be open sinceit is contained by the trough-like subdeck. The open ends of the slatsare now easier to seal because they are bounded only by the lowersurface of the slat and the outside walls of adjacent subdecks.

It should be noted that because the subdecks 30 support the slats 20, noadditional support is needed to support the slats even though preferredembodiments are made from light weight material. This can be compared toU.S. Pat. No. 4,727,978 which requires additional structures such astubular support members to support the slats. Another advantage overthis reference includes that no bearings are needed for the presentinvention. Finally, because the slat engagers 36 a, 36 b of the subdecks30 engage (form an additional seal) the slat legs 26 a, 26 b of theslats 20, vertical movement between the subdecks 30 and slats 20 issubstantially reduced or eliminated. Also, because this “seal” (betweenthe subdeck slat engagers 36 a, 36 b and the slat legs 26 a, 26 b) israised, it would be more difficult for particulate matter to escape thanthe lower connection between the slats and trough in U.S. Pat. No.4,727,978.

It should also be noted that, although preferred embodiments of thesubdecks 30 are able to catch and contain debris and particulate matter,the overlapping slats 20 prevents the majority of debris and particulatematter from entering the channels of the subdecks 30. This issignificant because it avoids problems associated with designs thatencourage matter to enter the channels (e.g. U.S. Pat. No. 4,611,708).

Method of Installation of the Double-Sealed, Bearingless, ReciprocatingSlat-Type Conveyor

An exemplary conveyor system 10 of the present invention may beinstalled using an exemplary basic installation method, the steps ofwhich would be modified based on variables including, but not limited tomaterials, sizes, locations, and intended applications. The figures ofthis application, particularly FIG. 6, are useful in understanding thismethod. First, the drive mechanisms (e.g. the cross-drives, cross-driveshoes, and the power units) are installed in, below, or otherwise nearthe load-holding compartment 12. Before the subdecks 30 are installed,both the number of moving slats 20 (as opposed to stationary side trimslats) and the clearances (e.g. front and rear clearances) should bedetermined and planned. If the number of moving slats 20 is even (evendeck number), an odd number of subdecks 30 are used with one subdeck 30centered on and anchored to the load-holding compartment 12 centerline.If the number of moving slats 20 is odd (odd deck number), an evennumber of subdecks 30 are used with two subdecks 30 centered about andanchored to the load-holding compartment 12 centerline. A spacer jig canbe used to position the remaining subdecks 30. End caps 50 arepositioned and secured at the ends of the subdecks 30 as shown (e.g.between two subdecks). Next, the deck slats 20 can be installed onto thesubdecks 30 by sliding the slats 20 onto the subdecks 30 from the end.When everything is in the correct position, the slats 20 may be securedto their respective cross-drive shoes 46. Side trim made from a whole ora partial (ripped) deck slat 20 may be added at this point. Also, asloped sheet with a wiper may be added at this point.

Tipper Retrofit Bearingless Reciprocating Slat-Type Conveyor Assembly

As discussed in the Background, there are many trailers produced for thesole function of being loaded through the open ceiling of the trailerwith municipal waste, being driven to a landfill, and being loaded ontoa tipping platform and tipped to great heights to dump the load of wasteout the rear door (gate). These trailers are most often called “tippertrailers.” Exemplary tipper trailers are shown and discussed in U.S.Pat. No. 6,019,568 to Bratlie, U.S. Pat. No. 6,860,695 to Chapman etal., and U.S. Pat. No. 7,100,972 to Booher. These references are hereinexpressly incorporated by reference in their entirety. Many tippertrailer operators find that they are no longer being routed todestinations that have tipping platforms. If the new destinations do nothave a tipping platform to unload the tipper trailer, the tipper traileris useless. The tipper retrofit reciprocating slat-type conveyorassembly described herein may be used to retrofit a tipper trailer witha reciprocating slat-type conveyor. The converted tipper trailer can beused at destinations that do not have a tipping platform.

A reciprocating slat-type conveyor can be created using a front mounthydraulic drive unit (fulfilling function of power unit 40 or a functionsimilar thereto) driving spaced apart slats installed on top of thetrailer's existing floor. The missing component is a lightweight quicklyinstalled reciprocating slat-type conveyor assembly. FIGS. 14-16 show atipper retrofit reciprocating slat-type conveyor assembly that islightweight quickly installed reciprocating slat-type conveyor assembly200 that includes slats 210. The lightweight reciprocating slat-typeconveyor assembly includes elongate hold down strips 220 (FIG. 15) andelongate guide trough subdecks 230 (FIG. 16) that support the slats 210.The shown reciprocating slat-type conveyor assembly is free fromdistinct bearing elements between the subdecks 230 and the slats 210.

As shown in detail in FIG. 15, each elongate hold down strip 220 isformed in a U shape (a base 222 a with upward fingers 222 b). Eachupward finger 222 b has subdeck engaging structure (shown as barbs 224).The shown barbs 224 extend outwardly from the top half of the upwardfingers 222 b. This hold down strip 220 is installed on the trailerfloor 202. In preferred embodiments, an elongate hold down strip 220 isinstalled parallel to and substantially adjacent (albeit with a smallspace therebetween) along the longitudinal sides if the floor 202 of thetrailer. Additional hold down strips 220 may be installed in thelongitudinal center of the floor 202 of the trailer or at spacedintervals on the floor 202 of the trailer.

As shown in detail in FIG. 16, the elongate guide trough subdecks 230are laid down to span the floor 202 of the trailer. The shown guidetrough subdecks 230 have a span 232 with two sides. At each side of thesubdeck span 232 there is an upside-down U-shaped slat side support 234.Projecting towards the span 232 from the slat side support 234 is a slatengaging structure (shown as barbs 236). On the end of the fingers ofeach upside-down U-shaped slat side support 234 are barb engagingstructures 238 to interact with the barbs 224 of the hold down strip220. Each guide trough subdeck 230 supports two slats 210, one on eachside of the upside-down U-shaped slat side supports 234.

Multiple guide trough subdecks 230 that extend the length of the trailerare positioned adjacent each other across the width of the trailer. Thetwo outer guide trough subdecks 230 are snapped onto hold down strips220 that have been installed on the floor 202. For each of the two outerguide trough subdecks 230, one side (the upside-down U-shaped slat sidesupport 234) is snapped down onto the hold down strip 220 so that thestructure 238 interacts with (shown as being longitudinally positionedunder) the barbs 224 of the hold down strip 220. Two guide troughsubdecks 230 near the center of the trailer may also be snapped downonto centrally located hold down strips 220. The rest of the guidetrough subdecks 230 may be allowed to float freely between these “helddown” guide trough subdecks 230.

The shown slats 210 have an upper surface 212 with a substantiallydownwardly projecting leg 214 on each side. Each leg 214 has an inwardlyprojecting subdeck engaging structure 216. Each slat 210 is supported bytwo guide trough subdecks 230. When the slats 210 are supported on thesubdecks 230 the subdeck engaging structure 216 engages the slatengaging structure (shown as barbs 236). The size of each guide troughsubdeck 230 determines the space between two adjacent slats 210.

In this preferred tipper retrofit, bearingless, reciprocating slat-typeconveyor assembly, the guide trough subdecks 230 may be made of a firstmaterial and the slats 210 are made of a second material dissimilar tothe first material. In this preferred double-sealed, bearingless,reciprocating slat-type conveyors, the second material is stiffer thanthe first material.

Since the slats 210 are guided and supported by the guide troughsubdecks 230 and since the guide trough subdecks 230 and slats 210 worktogether to maintain proper spacing between the slats 210 there is noneed for a separate “bearing” component. There is no need to fastenevery guide trough subdeck 230 to the floor 202 because the slats 210and guide trough subdecks 230 form an interlocking chain across thefloor 202. So just as a chain can be prevented from lifting by attachingonly several links separated by a distance so the slat system can beheld down by fastening (with hold down strips 220) only several guidetrough subdecks 230 separated by a distance across the floor 202.

The hold down strip 220 prevents the guide trough subdecks 230 fromlifting off the floor of the trailer. In preferred assemblies, no morethan four hold down strip 220 are required to support the whole trailerwidth of guide trough subdecks 230 and slats 210. In other words, thissystem requires relatively few fasteners or fasten points as comparedwith standard systems. Few fasteners or fasten points means much lessinstallation time and materials. The system is also considerably lighterweight than the standard system because it does not require metal guidebeams.

Although the retrofit, bearingless, reciprocating slat-type conveyorassembly described herein is discussed in terms of use with tippertrailers, it should be noted that the assemblies may be used withalternative types of trailers or other load-holding compartments oftransport vehicles.

Snap Together Bearingless Reciprocating Slat-Type Conveyor Assembly

Cross-members are well known in the art. U.S. Pat. No. 4,144,963 toHallstrom, U.S. Pat. No. 4,184,587 to Hallstrom, U.S. Pat. No. 4,785,929to Foster, U.S. Pat. No. 5,482,155 to Foster, U.S. Pat. No. 6,763,933 toWilkens, U.S. Pat. No. 7,152,729 to Wilkens, and U.S. Patent PublicationNo. 2003/0178546 to De Raad are all herein incorporated by reference intheir entirety.

FIGS. 17-27 show a snap together reciprocating slat-type conveyorassembly 300 that is free from distinct bearing elements between theslats 310 and the subdecks 330. The snap together reciprocatingslat-type conveyor assembly 300 is directly supported by thecross-members 302 of a trailer or other load-holding compartment of atransport vehicle. Each cross-member 302 is gripped by a plurality ofanchors 320. The subdecks 330 engage the anchors 320. The slats 310engage the subdecks 330. Put another way, the snap togetherreciprocating slat conveyor 300 is shown as having slats 310 guided andsupported by subdecks 330 that are, in turn, supported by trailercross-members 302. The subdecks 330 are attached to the cross-members302 using Y-shaped (in cross section) anchors 320.

In the shown snap together reciprocating slat-type conveyor assembly300, the anchors 320 grip different widths of cross-members 302 (or atleast the top of the cross-members 302). This is accomplished by usingopposing and interlocking anchors 320 that, when pushed together aroundthe cross-member top flange, cannot be separated.

The shown subdecks 330 are slippery plastic (e.g. anti-friction materialsuch as synthetic thermoplastic resin such as Teflon®, Delrin®,polyethylene, etc., or other suitable material having a low coefficientof friction) and the slats 310 are metal or other material that isstiffer than the plastic. In this preferred snap together bearingless,reciprocating slat-type conveyor assembly, the guide trough subdecks 330may be made of a first material and the slats 310 are made of a secondmaterial dissimilar to the first material. In this preferreddouble-sealed, bearingless, reciprocating slat-type conveyors, thesecond material is stiffer than the first material.

The subdecks 330 are oriented adjacent each other along the cross-member302 so that the subdecks 330 substantially span the width of theload-holding compartment. This orientation causes the maximum gap (shownin FIG. 20) between two adjacent slats 310 to be constrained by onesubdeck 330. The minimum gap (shown in FIG. 21) between two adjacentslats 310 is constrained by the relationship a central subdeck 330 andits two adjacent subdecks 330 (three consecutive subdecks 330) that aretogether supporting the two slats 310. Bearings between the subdecks 330and the cross-members 302 are not needed to properly constrain theminimum and maximum gaps between the slats 310.

Each of these subdecks 330 guides and supports two slats 310. The slats310 are prevented from moving vertically or laterally relative to thesubdecks 330 while being able to move longitudinally relative to thesubdecks 330.

Definitions

The term “seal,” as used in the present invention, is not generallymeant to mean a complete and absolute barrier. Instead, the term “seal”is meant to mean an intended and substantial barrier to entry.Accordingly, it is possible that some matter will pass the first seal 48a and enter the channel formed by the subdeck 30. Depending on thetolerances and the type of material, the seal may be almost complete.

It should be noted that some terms used in this specification are meantto be relative. For example, the terms “longitudinal” and “transverse”are meant to be relative and, if the system was rotated, the terms wouldchange accordingly. Similarly, the term “front” is meant to be relativeto the term “rear” and the term “top” is meant to be relative to theterm “bottom.” It should be noted that, unless otherwise specified, theterm “or” is used in its nonexclusive form.

All the references cited herein are incorporated by reference.

The terms and expressions that have been employed in the foregoingspecification are used as terms of description and not of limitation,and are not intended to exclude equivalents of the features shown anddescribed or portions of them. The scope of the invention is defined andlimited only by the claims that follow.

What is claimed is:
 1. A reciprocating slat conveyor for use in aload-holding compartment, said reciprocating slat conveyor comprising:(a) a plurality of laterally and substantially parallel longitudinaltrough-like subdecks made of a first material, said subdecks in a spacedrelationship so as to form a longitudinal space between adjacentsubdecks; (b) a plurality of longitudinal slats adjacent to and parallelto each other, said slats made of a second material dissimilar to saidfirst material, each slat having a slat top surface, a slat bottomsurface, a slat first longitudinal side edge, a slat second longitudinalside edge, and a longitudinal middle span corresponding to longitudinalspaces between adjacent subdecks, said longitudinal middle span beingunsupported by said subdecks, said longitudinal middle span being morethan 30% of the width of said slat; (c) each slat centrally locatedwithin said load-holding compartment in a sliding relationship with apair of adjacent subdecks and covering the longitudinal space betweensaid pair of adjacent subdecks, said pair of adjacent subdecksconducting the movement of said slat; and (d) each subdeck centrallylocated within said load-holding compartment longitudinally supportingtwo adjacent slats at or near a slat longitudinal side edge.
 2. Thereciprocating slat conveyor of claim 1 wherein said first material isstiffer than said second material.
 3. The reciprocating slat conveyor ofclaim 1 wherein said conveyor is free from distinct bearing elementsbetween said subdecks and said slats.
 4. The reciprocating slat conveyorof claim 1 wherein said slat first longitudinal side edge of one slatforms a first seal with and is in sliding relationship with said slatsecond longitudinal side edge of an adjacent slat.
 5. The reciprocatingslat conveyor of claim 1 wherein said slat first longitudinal side edgeof one slat overlaps with said slat second longitudinal side edge of anadjacent slat.
 6. The reciprocating slat conveyor of claim 1, furthercomprising a raised double-seal system comprising first seals and secondseals: (a) said first seals formed when said slat first longitudinalside edge of one slat is substantially coextensive and in slidingrelationship with said slat second longitudinal side edge of an adjacentslat; and (b) said second seals formed when upward side projections ofsaid subdeck are substantially coextensive and in sliding relationshipwith the slat bottom surface of the slats supported by said upward sideprojections.
 7. The reciprocating slat conveyor of claim 1, furthercomprising: (a) each longitudinal trough-like subdeck having a subdeckfirst upward side projection with a first slat engager thereon and asubdeck second upward side projection with a second slat engagerthereon; (b) said first slat engager engaging said slat bottom surfaceat or near said slat first longitudinal side edge; and (c) said secondslat engager engaging said slat bottom surface at or near said slatsecond longitudinal side edge.
 8. The reciprocating slat conveyor ofclaim 1, further comprising drive mechanisms, said drive mechanismspositioned in longitudinal spaces between adjacent subdecks.
 9. Areciprocating slat conveyor for use in a load-holding compartment, saidreciprocating slat conveyor comprising: (a) a plurality of laterally andsubstantially parallel longitudinal trough-like subdecks, said subdecksin a spaced relationship so as to form a longitudinal space betweenadjacent subdecks; (b) a plurality of longitudinal slats adjacent to andparallel to each other, each slat having a slat top surface, a slatbottom surface, a slat first longitudinal side edge, a slat secondlongitudinal side edge, and a longitudinal middle span corresponding tolongitudinal spaces between adjacent subdecks, said longitudinal middlespan being unsupported by said subdecks, said longitudinal middle spanbeing more than 30% of the width of said slat; (c) each slat centrallylocated within said load-holding compartment in a sliding relationshipwith a pair of adjacent subdecks and covers the longitudinal spacebetween said pair of adjacent subdecks, said pair of adjacent subdecksconducting the movement of said slat; (d) each subdeck centrally locatedwithin said load-holding compartment longitudinally supporting twoadjacent slats at or near a slat longitudinal side edge; and (e) araised double-seal system comprising first seals and second seals: (i)said first seals formed when said slat first longitudinal side edge ofone slat is substantially coextensive and in sliding relationship withsaid slat second longitudinal side edge of an adjacent slat; and (ii)said second seals formed when upward side projections of said subdeckare substantially coextensive and in sliding relationship with the slatbottom surface of the slats supported by said upward side projections.10. The reciprocating slat conveyor of claim 9 wherein said subdecks aremade of a first material and said slats are made of a second materialdissimilar to said first material, said first material being stifferthan said second material.
 11. The reciprocating slat conveyor of claim9 wherein said conveyor is free from distinct bearing elements betweensaid subdecks and said slats.
 12. The reciprocating slat conveyor ofclaim 9, further comprising: (a) each upward side projection having aslat engager thereon; and (b) each slat engager engaging said slatbottom surface at or near one of said slat longitudinal side edges. 13.The reciprocating slat conveyor of claim 9, further comprising: (a)wherein said upward side projections are a subdeck first upward sideprojection and a subdeck second upward side projection, said subdeckfirst upward side projection having an associated first slat engager,said subdeck second upward side projection having an associated secondslat engager; (b) each slat having a downwardly extending pair of legsincluding a first leg at or near said slat first longitudinal side edgeand a second leg at or near said slat second longitudinal side edge; (c)said first slat engager engaging said slat first leg; and (d) saidsecond slat engager engaging said second leg.
 14. A reciprocating slatconveyor for use in a load-holding compartment, said reciprocating slatconveyor comprising: (a) a plurality of laterally and substantiallyparallel longitudinal trough-like subdecks, said subdecks in a spacedrelationship so as to form a longitudinal space between adjacentsubdecks, each subdeck having a subdeck first upward side projectionwith a first slat engager thereon and a subdeck second upward sideprojection with a second slat engager thereon; (b) a plurality oflongitudinal slats adjacent to and parallel to each other, each slathaving a slat top surface, a slat bottom surface, a slat firstlongitudinal side edge, a slat second longitudinal side edge, and alongitudinal middle span corresponding to longitudinal spaces betweenadjacent subdecks, said longitudinal middle span being unsupported bysaid subdecks, said longitudinal middle span being more than 30% of thewidth of said slat, each slat having a downwardly extending pair of legsincluding a first leg at or near said slat first longitudinal side edgeand a second leg at or near said slat second longitudinal side edge; (c)each slat centrally located within said load-holding compartment in asliding relationship with a pair of adjacent subdecks and covers thelongitudinal space between said pair of adjacent subdecks, said pair ofadjacent subdecks conducting the movement of said slat; (d) each subdeckcentrally located within said load-holding compartment longitudinallysupporting two adjacent slats at or near a slat longitudinal side edge;(e) said first slat engager engaging said slat bottom surface and saidslat first leg; and (f) said second slat engager engaging said slatbottom surface and said second leg.
 15. The reciprocating slat conveyorof claim 14 wherein said slat first longitudinal side edge of one slatforms a first seal with and is in sliding relationship with said slatsecond longitudinal side edge of an adjacent slat.
 16. The reciprocatingslat conveyor of claim 14 further comprising a raised double-seal systemcomprising first seals and second seals: (a) said first seals formedwhen said slat first longitudinal side edge of one slat is substantiallycoextensive and in sliding relationship with said slat secondlongitudinal side edge of an adjacent slat; and (b) said second sealsformed when said slat engagers are substantially coextensive and insliding relationship with the slat bottom surface of the slats supportedby said upward side projections.
 17. The reciprocating slat conveyor ofclaim 14, said first slat engager engaging said slat bottom surface ator near said slat first longitudinal side edge, and said second slatengager engaging said slat bottom surface at or near said slat secondlongitudinal side edge.
 18. The reciprocating slat conveyor of claim 14wherein said subdecks are made of a first material and said slats madeof a second material dissimilar to said first material, said firstmaterial being stiffer than said second material.
 19. The reciprocatingslat conveyor of claim 14 wherein said conveyor is free from distinctbearing elements between said subdecks and said slats.